Conventionally, a connector or a syringe has been used to mix a hypertonic amino acid preparation with a total parenteral nutrition base solution. In preparing an injection using antibiotic powder sealed in a vial, distilled water for injection or physiological saline is withdrawn by a syringe and injected into the vial to dissolve the antibiotic.
Infusion fluids are in many cases administered to patients by intravenous drip infusion. Of the different solutions that make up the infusion fluids, amino acid solutions and glucose solutions react with each other when mixed and are therefore stored in different compartments that are defined by peelable separators within an infusion bag. Upon use, the infusion bag is pressed from the outside to force the separators to peel, allowing the solutions to mix.
Upon administration of an infusion fluid to a patient by intravenous drip infusion, small amounts of additional drugs need to be added to the base solution, such as amino acid solution and glucose solution, of the infusion fluid depending on the condition of the patient. Among such drugs are trace minerals, vitamins, analgesics, fat infusions, antibiotics, minerals and cardiac stimulants. In general, mixing of the small amount of the drugs with the base solution is performed in a clean booth in the hospital. During the mixing process, a communicating tube or a syringe is used to inject the drugs into an infusion bag containing the infusion fluid. Care must be taken to prevent contamination of the fluid with bacteria.
When small amount of drugs are mixed with an infusion fluid, it is often undesirable to leave the mixed infusion fluid prior to administration because many of the drugs readily decompose once mixed. For example, decomposition of vitamin B1 is facilitated by sulfite, an oxidizing agent used to oxide amino acids in the total parenteral nutrition base solution. When mixed, these drugs react with each other to form contaminants or facilitate the decomposition of each other. Some drugs are preferably administered at intervals. Generally provided in a volume of about 1 L, infusion fluids are not suitable for intricate adjustment and can only be mixed with a limited number of additional drugs.
Mixing and dissolving the additional drugs in infusion fluids involves the use of connector tubes and syringes, which not only makes the process complicated, but also requires a number of additional operations including connecting connector tubes and syringes and piercing bags of different solutions with a needle. Thus, the chance is high that the infusion fluids are contaminated with bacteria during the mixing process. Furthermore, the drugs remaining in syringes and the like after these operations lead to a considerable loss.
In an effort to counteract these problems, different types of premix infusion bags have been developed. For example, Patent Document 1 describes a premix infusion bag, which includes: a flexible infusion bag, a bottle needle directly attached to at least one part of the bag, a passage formed through the bottle needle in communication with the interior of the bag, a seal arranged in the passage of the bottle needle so that it shuts off the communication between the bottle needle and the interior of the bag, and a breakable element arranged in the passage so that it can be broken to open the communication between the bottle needle and the interior of the bag. The seal is arranged inside the bag and the breakable element is arranged between the inner periphery of the bag and the seal.
Patent Document 2 discloses a medical infusion bag, which includes: a first chamber, a second chamber and a single sub-chamber that are each defined by flexible resin film and can each pack a pharmaceutical fluid; and easy-peel seals disposed between the first and the second chambers and between the second and the sub-chambers, respectively, the easy-peel seals peeling under different pressures. Upon use, the pharmaceutical solution in the first chamber or the second chamber is mixed with the pharmaceutical solution in the sub-chamber via a nozzle extending from the sub-chamber.    Patent Document 1: Japanese Patent Publication No. Hei 5-52748    Patent Document 2: Japanese Patent Laid-Open Publication No. 2000-316951
The medical infusion bags disclosed in these patent documents each have a configuration in which a flexible plastic bag has separate compartments for individual infusion fluids. Upon use, the compartments are connected in fluid communication with each other, for example, by applying external force to mix the infusion fluids. This feature inevitably limits the number of infusion fluids that can be packed in a single medical bag. As a result, the applicability of these infusion bags is significantly limited. Thus, there is a need for a simple communicating needle that can be used with a wide variety of medical infusion bags to connect two or more containers in fluid communication with each other. It is necessary that such a communicating needle does not have the problems of infusion fluids remaining in the containers or infusion fluids contaminated with debris resulting from the broken seals.